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No Model.)

N. McGARTY.

ELECTRIC ARC LAMP.

No. 325,424. Patented Sept. 1, 1885.

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UNITED STATES PATENT Grinch-Q NORMAN MOGARTY, OF HOOSIOK, N EWV YORK, ASSIGNOR TO JOHN 13. TIBBITS, OF SAME PLACE.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 325,424, dated September 1, 1885.

(No model.)

To all whom it may concern:

Be it known .that I, NORMAN MoCAnrY, of Hoosick, in the county of Rensselaer. and State of New York, have invented a new Improvement in ElectricArc Lamps; and I do hereby declare the following, when taken in connection with accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in Figure 1, a side View showingthe principal magnet, carbons, the shunt-magnet. open,with the commutator as in the working condition;

1 Fig. 2, a top view of the commutator, showing the brushes in connection therewith; Fig. 3, a side view of the shunt-magnet and the commutator in position during the closing or opening movement when the non-conducting surface stands at an intermediate position,

contact being made with both brushes.

This invention relates to an improvement in electric-arc lamps in which a shunt-magnet is employed, arranged to break the circuit 2 through one line after it is completed in another, and is an improvement upon the invention for which Letters Patent of the United States No. 305,096 were granted to me September 16, 1884.

0 The object of the invention is to produce the automatic action of the shunt through a commutator; and the invention consists in the construction hereinafter described, and par ticularly recited in the claim.

For convenience of illustration I show the principal magnet, the shunt, and the carbons detached from the usual lamp mechanism, and arranged side by side instead ofin their usual relation to each other.

A represents the principal magnet; 13, the shunt-magnet; O, the upper-carbon holder, andD the lower-carbon holder; a, the armature of the principal magnet, and b the armature of the shunt-magnet, the said armature Z) hinged at one end of the magnet, and so as to swing toward and from its pole at the opposite end in closing and opening, substantially the same as in my previous patent.

E is the commutator-cylinder, hungin bearings F F in metal connection with the base Gr. The commutator-cylinder is provided at one part of its circumference with a surface, II, of non-conducting material or fiber. Rotary movementis imparted to the commutatorcylinder by means of an arm, (I, attached to the armature and extending downward, and from which a connecting-rod, 0, extends to the commutator, and is connected thereto atf at a point eccentric to the axis ofthe commutator, and so that as the armature b of the shunt 6 magnet closes it will impart corresponding rotation to the commutator, as indicated in broken lines, or opening will return the co1nmutator, as indicated in Fig. 1.

I is one brush in connection with a post, J, 5 and L the other brush in connection with a like post, M. The fibrous surface H of the machine when the armature b of the shuntmagnet is in its open position, stands in contact with the brush I, leaving the otherbrush, L, bearing upon the surface of the cylinder; but when the armature b of the shunt-magnet closes then the cylinder is turned to take the fibrous or non-conducting surface H from contact with the brush I and bring it into contact with the brush L; but the two brushes stand in such relation to each other and to the non-conducting surface II that at an intermediate position between the opening and closing of the shunt the non-conductor H 8 stands between the two, as indicated in Fig.

3, so that both brushes at that time bear upon the surface of the commutator.

N represents the incoming line, and is connected to the post J of the brush I, and from 8 5 this line a branch, 0, leads to one end of the coil of the shuntmagnet. From the same post J a line, 1?, leads to one end of the coil of the principal magnet. From the other end of the coil of the principal magnet a line, It, 93 leads to the post M of the brush L. From the other end of the coil of the shunt-magnet a line, S, leads to the lower-carbon holder, thence out through U, and from the base of the commutator a line, T, leads to the upper- 95 carbon holder. The armature of the shuntmagnet is held away from its pole bya spring, W, or otherwise, the said spring serving to resist the closing movement of the shunt in the usual manner. In the working condition the shunt-armature is open and the commutator is in magnetic connection with the brush L, but

out out from such connection with the brush I by the interposed non-conducting material H. The circuit is now through the main line N to the post J, thence through the line P to the main magnet, thence through the post H to the brush L through the cominutator-cylindcr to the base, thence to the upper-carbon holder, thence out through the lower-carbon holder to the line U. As the carbons are consumed and the are thereby increased, a portion of the current is shunted, that current gradually increasing as the arc increases until the current be strong enough to overcome the spring WV of the shunt-armature. lhen that armature will be drawn toward its pole, thereby communicating rotation to the commutator, taking the non-conducting surface H from contact with the brush I, and as the armature is finally closed that non-conducting surface is brought into contact with the brush L, thereby breaking the electrical contact between the brush L and the commutator and bringing the commutator into electrical contact with the brush I. In this condition the current is shunted from the principal magnet A, breaking the circuit through that magnet, the feeding of the carbons then takes place in the usual manner, the arc is restored, the shunt-magnet loses its power in the usual manner, the armature opens, the commutator is returned to its first condition, or in contact with the brush 1. In

such turning ofthe commutator contact is made between the commutator and the brush I before it is broken between the commutator and the other brush,- L; hence the circuit through the principal magnet cannot bebroken before it is completed through the shunt, or vice versa; but the main current may be gradually broken one brush makes electrical contact before the h other brush escapes from the non-conducting surface.

I claim In an electric-arc lamp, the combination of the principal magnet and the shunt-magnet,

the armature of the shunt-magnet hinged to produce a vibratory movement in breaking and closing the main circuit, a commutator the cylinder of which is adapted for partial rotation, an arm extending from the armature of the shunt-magnet into connection with the commutator, and whereby under the movement of the said armature a rotary movement will be imparted to the commutator, and two brushes arranged to bear upon the surface of the said commutator, the commutator constructed wit-h a non-conducting surface between the bearing points of said brushes, but of less extent than the distance between said bearingpoints, substantially as and for the purpose described.

NORMAN MOOARTY.

*itnesses:

GEORGE H. MYERS, D. R. GRIFFITH. 

